The mpk-1ab mRNA was abundant in both GL+ and GL- animals, but mpk-1b mRNA was very low or undetectable in GL- animals. Therefore, mpk-1b appears to be enriched in the germline.
MPK-1A was present in both GL+ and GL- animals, but MPK-1B protein was found only in GL+ animals. Thus mpk-1b RNA and its MPK-1B protein are predominantly expressed in the germline.